Shaped charge devices



July 5, 1966 N. G. OWENS 3,259,064

SHAPED CHARGE DEVI CES Filed July 8, 1964 /Vevr/ 6. OWflJ INVENTOR.

)5 BY If/WM United States Patent 3,259,064 SHAPED CHARGE DEVICES NevylGregory Owens, Houston, Tex., assignor to Schlurnberger Weil SurveyingCorporation, Houston, Tex., a corporation of Texas Filed July 8, 1964,Ser. No. 381,117 2 Claims. (Cl. 10224) This invention relates to shapedexplosive charges for use in perforating a well; and, more particularly,to apparatus and methods for securing shaped explosive charges within acase or container.

Where explosive shaped charges for perforating a well are to be mountedon expendable carriers, the shaped charges must be encapsulated andfluidly sealed within a frangible case to protect the explosive fromfluids within the well bore. It is recognized by those skilled in theart that when the charges are detonated, these cases must besubstantially broken up so as to leave only small particles in the wellbore. Accordingly, it has become customary to fabricate cases for shapedcharges from such highly disintegrable materials as aluminum and glass.These cases are typically formed in two parts, a charge container and acover, which are adapted to be joined and sealed along their abuttingsurfaces to form a completely sealed case. A transverse recess along theouter surface of the rearward end of the container portion of the caseis suitably arranged for receiving and securing a strip of detonatingcord, such as Primacord.

It will be appreciated, of course, that to ensure reliable operation ofthe shaped charge device, the booster explosive at the base of theencapsulated charge must be maintained within detonating proximity ofthe detonating cord outside of the case. Thus, it is important that theshaped charge and its booster be suitably secured within the case to becertain that they can not shift from a predetermined position.Accordingly, it has been customary, heretofore, to form an internalshoulder in the cover which is suitably arranged and adapted to engagethe forward peripheral edge of the shaped charge and maintain the baseof the charge near the rear wall of the case within detonating proximityof the detonating cord. Because of normal dimensional variations usuallyfound in pre-formed shaped charge pellets as well as in massproducedglass cases, it is sometimes necessary to select and match a givenexplosive pellet to particular case portions or else custom-fit eachshaped pellet into a particular case.

Accordingly, it is an object of the present invention to provide new andimproved means for fluidly sealing and securing shaped charges within acharge case.

This and other objects of the present invention are accomplished byinserting a shaped charge into the container portion of a two-part case;coating an abutting surface of the cover and container as well as anadjacent interior surface of the cover with a hardenable adhesivesealing material; and bringing the case portions together to extrude aportion of the adhesive material around the forward edge of the shapedcharge so that, when hardened, the adhesive provides a forward supportof the charge.

The novel features of this invention are set forth with particularity inthe appended claims. The present invention, both as to its organizationand manner of operation together with further objects and advantagesthereof, may best be understood by way of illustration and example of atypical embodiment when taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is an elevational view, with a portion thereof being incross-section, illustrating a typical method for assembling a shapedcharge device in accordance with the principles of the presentinvention; and

FIGURE 2 is a view in longitudinal cross-section show- "ice ing arepresentative shaped charge device as arranged and assembled inaccordance with the principles of the present invention.

Turning now to the drawings, a shaped charge device 10 is comprised of atwo-part case 11 having a dished cover portion 12 and a generallycylindrical, hollowed container portion 13 for receiving a typicalcyclindrically shaped explosive charge 14. As is customary, the shapedcharge 14 has a pre-formed pellet 15 of a suitable highexplosivematerial, such as RDX, having an axially aligned, frusto-conical cavitydiverging outwardly toward its forward end. A hollowed, complementarilyshaped liner 16 of a suitable metal is disposed in the frusto conicalcavity with the base of the liner terminating at the forward peripheraledge 17 of the shaped charge 14. A suitable booster charge 18 isdisposed in a recess formed in the rear wall 19 of the container portion13.

The mating abutting surfaces 20, 21, respectively, of the cover andcontainer portions 12, 13, are suitably prepared to ensure that afluid-tight seal will be made whenever these portions are sealinglyjoined. On the exterior of the rear wall 19 of the container portion 13,two spaced-apart, axially projecting lugs 22 form a transverse groove 23suitably sized and adapted to sungly receive and retain a suitabledetonating cord (not shown) such as, for example, Primacord. Inaddition, spacedapart, lateral projections 24 are centrally located onopposite sides of the container portion 13 to form opposed peripheralgrooves 25 suitably sized and adapted for mounting of the assembledshaped charge device 10 to an expendable-type carrier (not shown).

Turning now to the new and improved means for securing the shaped charge14 within its case, the container-engaging surface 20 of the coverportion 12 and the adjacent interior surface portions of the cover arecoated, as shown in FIG. 1, with a layer of an appropriate hardenableadhesive material 26, such as Epoxylite No. 810 manufactured by TheEpoxylite Corporation of South El Monte, California. A sufiicient amountof the adhesive 26 is disposed around the interior surface of the coverportion 12 to ensure that a portion of the adhesive will be squeezedupwardly around the shaped charge 14 and project slightly over itsforward peripheral edge 17 whenever the cover is moved in the directionof the arrows 27 toward the container portion 13. Similarly, asufficient quantity of the adhesive 26 is spread around the matingsurface 20 to totally cover the mating abutting surfaces 20 and 21, andleave a slight excess amount thereof to be extruded outwardlytherearound and form a peripheral sealing bead 28 as shown in FIG. 2.

As the cover portion 12 is moved in the direction of the arrows 27toward the container portion 13, a portion of the adhesive 26 isdisplaced upwardly over the forward edge 17 of the shaped charge 14 andforms an annular bead 29 (FIG. 2). Similarly, as the two case portions12 and 13 are pressed together, another portion of the adhesive material26 is extruded inwardly around the charge 14 to form an annular support30 between the charge 14 and the container portion. The remainder of theadhesive 26 is squeezed outwardly between the surfaces 20, 21 and formsthe peripheral sealing head 28 at the junction of the abutting surfaces.

Thus, upon hardening of the adhesive material 26, the two case portions12 and 13 are sealingly secured together by the peripheral bead 28 andthe adhesive between their mating surfaces 20, 21; the hardened head 29provides a forward abutment which retains the shaped charge 14longitudinally fixed Within the case 11; and the hardened annularsupport 30 holds the shaped charge in a laterally fixed position.

Accordingly, it will be appreciated that the present invention securelyretains the shaped charge 14 in the case 11 without an integral shoulderbeing required in the cover portion 12 as well as eliminates thenecessity of maintaining close dimensional tolerances in either portionof the case 11 or in the pre-formed shaped charge.

While a particular embodiment of the present invention has been shownand described, it is apparent that changes and modifications may be madewithout departing from this invention in its broadest aspects; andtherefore, the aim of the appended claims is to cover all such changesand modifications as fall within the true spirit and scope of thisinvention.

What is claimed is:

1. A shaped charge device comprising: a frangible, multi-part, hollowcharge case sized and adapted to receive an explosive charge, said caseincluding a dished cover portion and a container portion having abuttingmarginal surfaces adapted to be joined and sealed together; shapedexplosive charge means having a forward peripheral edge of selecteddiameter received in said case; and firming adhesive means for sealinglyjoining said case portions and having a portion abuting and securingsaid charge means against forward longitudinal movement relative to saidcase and being the sole forward support for the charge means within thecase, the case having an internal diameter larger than the selecteddiameter forwardly of said forward peripheral edge of the charge means.

2. A shaped charge device comprising: a frangible,

multi-part, hollow charge case sized and adapted to receive an explosivecharge, said case including a dished cover portion and a containerportion having abutting marginal surfaces adapted to be joined andsealed together; shaped explosive charge means having a forwardperipheral edge of selected diameter received in said case; and afirming adhesive material having a first portion operatively disposedbetween said abutting surfaces for joining and fluidly sealing said caseand a second portion extending into said case and including a hardenedbead of adhesive material surrounding and operatively engaged with saidforward peripheral edge forming a forward abutment for securing saidcharge means against forward longitudinal movement relative to said caseand being the sole forward support for the charge means Within the case,the case having an internal diameter larger than the selected diameterforwardly of said forward peripheral edge of the charge means.

References Cited by the Examiner UNITED STATES PATENTS 2,629,325 2/1953Sweetman l0220 BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner.

V. R. PENDEGRASS, Assistant Examiner.

1. A SHAPED CHARGE DEVICE COMPRISING: A FRANGIBLE, MULTI-PART, HOLLOWCHARGE CASE SIZED AND ADAPTED TO RECEIVE AND EXPLOSIVE CHARGE, SAID CASEINCLUDING A DISHED COVER PORTION AND A CONTAINER PORTION HAVING ABUTTINGMARGINAL SURFACES ADAPTED TO BE JOINED AND SEALED TOGETHER; SHAPEDEXPLOSIVE CHARGE MEANS HAVING A FORWARD PERIPHERAL EDGE OF SELECTEDDIAMETER RECEIVED IN SAID CASE; AND FIRMING ADHESIVE MEANS FOR SEALINGLYJOINING SAID CASE PORTIONS AND HAVING A PORTION ABUTTING AND SECURINGSAID CHARGE MEANS AGAINST FORWARD LONGITUDINAL MOVEMENT RELATIVE TO SAIDCASE AND BEING THE SOLE FORWARD SUPPORT FOR THE CHARGE MEANS WITHIN THECASE, THE CASE HAVING AN